The present invention relates to flush valves for use in connection with toilet devices such as urinals and water closets, and more specifically, to a piston-type flush valve. More particularly, the invention relates to a relief valve head intended for aggressive water conditions that can be used in more than one type of piston flush valve.
The relief valve functions as a semi-dynamic barrier between a pressurized water chamber above the flushometer piston and the fixture discharge outlet which is at a pressure close to atmospheric. To initiate the flush cycle, the relief valve is tipped by depressing the flushometer handle, thus venting the pressure chamber above the piston to the fixture outlet. This sudden pressure imbalance causes the piston to move upward from its seat and discharge a controlled volume of water. The relief valve returns to its rest position as soon as the flushometer handle or other actuation mechanism is released and the piston travels upward away from its seat area. The entire relief valve assembly contributes to controlling the flush volume delivered by an operating cycle of the valve. The flush volume is directly proportional to the length from the seating area of the head of the relief valve to the point at which the handle plunger strikes the relief valve stem.
The present invention provides a relief valve which has been designed specifically to accommodate two different size flushometer pistons. There are a plurality of points around the perimeter of the relief valve that function as a centering means for the smaller piston. The inward curve of the perimeter between these points acts to allow water to flow past when tipped and to clear alignment pins found on some old style pistons sold by Sloan Valve Company, the assignee of the present application, under the trademark NAVAL. There are also a plurality of standing ribs on the relief valve shoulder that function to capture a spring used on the larger piston of the NAVAL brand flush valve. The relief valve spring functions to insure proper closing of the valve and a tight seal at low pressures between the valve and the seat around the relief valve vent passage. The raised center area or hub of the relief valve accommodates a spring used on the GEM-style flush valves.
It is particularly advantageous that the relief valve shown and described herein is suitable for use on two different size and style of piston-type flushometers, both the GEM and the NAVAL products. This provides economy of scale in that one single part has multiple uses. Both the GEM and NAVAL flushometers are used in aggressive water conditions that include some combination of sediment and gray or sea water. The relief valve is particularly suitable in such an environment.
The present invention relates to piston-type flush valves for use with urinals and water closets and more specifically to an improved relief valve for use in the piston assembly.
A primary purpose of the invention is to provide a relief valve which is suitable for use in more than one style and size of piston-type flush valve.
Another purpose of the invention is to provide an improved relief valve head which has a perimeter which functions as an alignment or centering device for the relief valve.
Another purpose is to provide a relief valve as described which provides for centering the relief valve spring on larger size piston-type flushometers and for supporting the relief valve spring on smaller piston-type flushometers.
Another purpose of the invention is to provide a relief valve as described which insures complete closing of the relief valve but yet adequate water flow around it when the flush valve is operated.
Other purposes will appear in the ensuing specification, drawings and claims.